Method and apparatus for forming wheel rims and the like



Jan. 17, 1967 G. E. GOLLWITZER 3,293,213

METHOD AND APPARATUS FOR FORMING WHEEL RIMS AND THE LIKE 4 Sheets-Sheet 1 Filed Aug. 20, 1963 TNVENTOR.

1967 G. E. GOLLWITZER METHOD AND APPARATUS FOR FORMING WHEEL RIMS AND THE LIKE 4 Sheets-Sheet 2 Filed Aug. 20, 1963 HNVENTOR. I 6 76 I 60/502716).

Jan. 17, 1967 G, E. GOLLWITZER 3,298,218

METHOD AND APPARATUS FOR FORMING WHEEL RIMS AND THE LIKE Filed Aug. 20, 1963 4 Sheets-Sheet 3 INVENTQ Jan. 17, 1967 G. E. GOLLWITZER METHOD AND APPARATUS FOR FORMING WHEEL RIMS AND THE] LIKE Filed Aug. 20, 1963 4 Sheets-$heet 4 III IPII 1.3

INVENTOR.

A 071ml United States Patent 3,298,218 METHOD AND APPARATUS FOR FURMING WHEEL RIMS AND THE LIKE George E. Gollwitzer, Belle, Mich., assignor to Kelsey- Hayes Company, Romulus, MlClL, a corporation of Delaware Filed Aug. 20, 1963, Ser. No. 303,286 6 Claims. (Cl. 72355) This invention relates to a method and apparatus for forming wheel rims and the like and more particularly to a die apparatus and method for pressing an annular blank to the desired cross-sectional contour of the rim.

In using apparatus of this type the commercially available stock may vary in thickness from a high tolerance of approximately ten thousandths of an inch to a low tolerance of approximately seven thousandths of an inch. Ordinarily, the stock varies in thickness i.007 or .014 or more than 10% in stock having a thickness of .125. If the die segments are set to operate on high tolerance stock, they will not function to finally shape the low tolerance stock. On the other hand, if the die segments are set for low tolerance stock, the use of high tolerance stock will act to score the dies. Also, the tolerances of the stock are not uniform so that it is impractical to set the dies to operate effectively on all types of stock.

It is therefore an object of this invention to provide a method and apparatus for pressing a blank to the desired cross-sectional contour irrespective of the thickness of the stock within the tolerances usually encountered in commercially available stock.

Another object of the invention is to provide an apparatus embodying an outer die member cooperating with inner die segments, together with means for moving said inner die segments into shaping engagement with the blank and means for further moving said inner die segments into engagement with the blank to compensate for any variations in the thickness of the stock of the blank.

The various objects and advantages, and the novel details of construction of one commercially practical embodiment of the invention, will become more apparent as this description proceeds, especially when considered in connection with the accompanying drawings, in which:

FIGURE 1 is a cross sectional View through a rim forming apparatus embodying the invention showing the die segments in separated position;

FIGURE 2 is a similar view showing the die segments in closed position for pressing the blank to the desired cross-sectional contour;

FIGURE 3 is a sectional view taken substantially on the plane indicated by line 33 in FIGURE 2;

FIGURE 4 is an enlarged sectional elevational view taken substantially on the plane indicated by line 44 in FIGURE 2;

FIGURE 5 is an enlarged fragmentary sectional view taken on line 5-5 in FIGURE 4;

FIGURE 6 is a detail sectional view taken on line 6-6 in FIGURE 4; and

FIGURE 7 is a cr0ss-sectional view of the blank in a preliminary form.

The apparatus of this invention may be employed in various environments, one of which is shown in the accompanying drawings in which there is provided a base 10 provided with end members 11 which may be of inverted U-shape in cross-section and a top frame member 12 connects the two end frame members 11, as shown in FIGURES 1 and 2. Extending horizontally across each end frame member 11 is a cross member 13 upon which a piston and cylinder device 14 is mounted. The top frame member 12 provides means for supporting a piston and cylinder device 15 which is provided with a piston 3,298,218 Patented Jan. 17, 1967 rod 16. The piston and piston rods of the devices 14 are not shown.

The device of this invention comprises an upper die member 20 and a lower die member 21. The lower die member may be fixed to the base 10 by means of a threaded rod member 17 and the upper die member 20 is fixed to the piston rod 16 for movement toward and away from the die member 20. These die members 20 and 21 are adapted to receive the blank B illustrated in FIGURE 7 or therebetween. The blank B consists of an annulus which has preferably previously been rolled to provide the cross-sectional shape shown in FIGURE 7. This blank is inserted between the die members 20 and 21 after they have been separated, as shown in FIGURE 1.

The mating forming dies consist of a plurality of lefthand die segments 25 and a plurality of series of righthand die segments 26. Preferably, although not necessarily, there are six die segments 25 and six die segments The mating profiles of the die members 20 and 21 and of the die segments 25 and 26 is such as to form the blank B into the final shape shown in full lines in FIGURE 2. The blank B, before being shaped to final form, is shown by dotted lines B in FIGURE 2.

The reference character 30 indicates two ram members which are adapted to move toward and away from one another on an axis at right angles to the movement of the die members 20 and 21. Each ram member 30 is provided with a bracket 31 connected to the piston rod of the piston and cylinder device 14 so as to be movable from the position illustrated in FIGURE 1 to the position illustrated in FIGURE 2. The brackets 31 are connected to the ram members 30 by means of bolts 32.

Each ram member 30 may be formed with an integral or separate shroud member 33. In the embodiment of the invention illustrated the shroud members 33 are formed as separate members and are secured by bolts 34 to the ram member 30. Each shroud member 33 is adapted to encircle the die members 20 and 21 in the closed position of the dies and thus act to hold these die members in fixed position with respect to one another during the shaping operation.

The die segments 25 and 26 constitute the inner die segments and each of these die segments is keyed to a ring-like plate 40 secured to the ram 31 by means of bolts 41. The reference character 42 indicates a tongue and groove sliding connection between the inner die segments 25 or 26 and then corresponding ring member 40. Thus, the inner die segments may move from the radially inner position illustrated in FIGURE 1 to the blank shaping position illustrated in FIGURE 2.

Each inner die segment 25 or 26 is urged radially inwardly by means of a spring 43 engaging a pin 44 carried by the die segment 25 or 26. Each spring 43 is mounted in the ring member 30 and a plug 45 threaded thereinto forms an abutment for the spring 43. The reference character 46 indicates knockout apertures so that the pins 44- may be removed and replaced.

In normal operation of the device, the rams 30 are moved from the position illustrated in FIGURE 1 to that illustrated in FIGURE 2 to bring the inner die segments 25 and 26 into shaping engagement with the blank B. However, as pointed out hereinbefore, the thickness of the stock of the blank B varies considerably so that if the dies are set to operate on one thickness of stock, they will not elfectively shape the rim if the. stock is of a different thickness. In commercially available stock the thickness varies from a low tolerance of seven thousandths of an inch to a high tolerance of ten thousandths of an inch and, possibly, more. It is for the purpose of compensating for these differences in stock thickness that the present invention was devised.

Each of the die segments 25 and 26 has its inner surface formed with a cam surface 50. These combined cam surfaces 50 form frusto-conical recesses at the inner sides of both sets of die segments 25 and 26. Cooperating with the cam surfaces th of each die segment or 26 is a cam member 51 which may be of annular configuration. Each cam member 51 is secured by bolts 52 toa piston 53 operating in a cylinder 54 carried by the ram 30. A conduit 55 is adapted to conduct hydraulic fluid to the cylinder 54 to actuate the piston 53. A limit switch (not shown) is provided to open a valve to permit the entrance of hydraulic medium to the conduit 55 to move the piston 53 at the inner end of each stroke of the ram 30. This action of the piston 53 serves to move the cam member 51 axially inwardly to further move the die segments 25 and 26 radially outwardly.

If the stock is of high tolerance, that is, in the range of ten thousandths of an inch thickness, the Wedges 511 will not move and, hence, the inner the segments 25 and 26 will not be displaced. If, however, the thickness of the stock is less, the wedges 51 will be moved to further force the inner die members radially outwardly into shaping engagement with the blank B to compensate for any clearance between the inner die segments and the blank. Thus, irrespective of variations in the thickness of the stock, the blank B will be shaped to its final desired profile.

While not illustrated, the piston 53 may be operated by a surge unit in which the hydraulic fluid is pressured by air pressure triggered by the previously mentioned limit switch at the end of each stroke of the ram 30. Thus, after the ram has moved the inner die segments 25 and 26 into shaping position, the additional movement of the inner die segments is imparted thereto depend ing on the thickness of the stock of the blank B.

As illustrated in FIGURES 4, 5, and 6, each of the segments 25 and 26 is secured to its ring member by means of bolts which are solidly threaded into the die segments 25 or 26 as at 611. These bolts pass through enlarged apertures 63 in the ring member 46 so as to permit relative radial movement of the die segments 25 and 26, as will be apparent.

As illustrated in FIGURE 3, the shroud 33 completely surrounds the upper and lower die members 20 and 21 to hold the same tightly together during the shaping operation. As also shown in this figure, the wedge member 51 is preferably provided with ribs 7@ which engage keyways 71 in the die segments 25 or 26 to provide a sliding interlocking engagement between each wedge member 51 and inner die segments 25 and 26. This is clearly illustrated in FIGURE 3.

As also illustrated in FIGURE 3, the base is provided with guides 72 which engage in mating grooves '73 in the shroud 33 and the rams 30 so as to properly guide these members in their movement to and from shaping position.

In operation, a blank B which has preferably been previously shaped by rolling to the approximate shape illustrated in FIGURE 7 is placed on the lower die member 21 and the piston and cylinder device 15 is actuated to move the upper die member 20 from the position illustrated in FIGURE 1 to that illustrated in FIGURE 2. Thereupon, the piston and cylinder device 14 are actuated to move the rams 3G and the inner die members 25 and 26 into shaping position illustrated in FIGURE 2. At this time the blank B has been shaped and has assumed the full line profile illustrated in FIGURE 2. Thereupon, the limit switch (not shown) is actuated to supply hydraulic medium through the conduit 55 to the cylinder 54 to actuate the pistons 53 to move the wedges 51 axially inwardly. If the thickness of the stock of the blank B is of low tolerance, that is, thinner than normal, the wedges 51 will further move the inner die segments 25 and 26 radially outwardly to take up any clearance between the inner die segments and the blank and finally shape the blank. Inasmuch as the outer die members 20 and 21 are held tightly in shaping position by the shrouds 33, air may be employed in the piston and cylinder device 15.

From the foregoing, it Will be seen that there is provided a method and apparatus for pressing a blank to the desired cross-sectional contour irrespective of the thickness of the stock within the tolerances usually encountered in commercially available stock.

While a commercially practical embodiment of the invention has been described and illustrated herein somewhat in detail, it will be understood that various changes may be made as may come Within the purview of the accompanying claims.

What is claimed is:

I. An apparatus for forming a rim from an annular blank including outer die means operable to confine the blank on the radially outer periphery thereof, a pair of oppositely movable rams movable axially into the blank, 81 pair of inner dies carried one on each of said rams, each of said inner dies comprising a plurality of die segments engageable with the radially inner periphery of a blank enclosed by said outer die means to form said rim upon the movement of said rams toward one another, and wedge means carried by each of said rams for radially expanding said die segments and means for actuating said wedge means upon the completion of the movement of said rams toward one another.

2. The structure set forth in claim 1 including spring means normally biasing said die segments in a radially inward direction.

3. The structure set forth in claim 1 in which said outer die means includes a pair of opposite outer die members movable toward and away from one another.

4. The structure set forth in claim 3 including shroud means carried by said rams operable to move into confining engagement with means carried by said outer die members for restraining movement of said outer die members away from one another as the blank is being formed by said die segments during the movement of said rams toward one another.

5. The structure set forth in claim 1 in which said last named means comprises fluid pressure operated means.

6. The structure set forth in claim 1 in which said last named means includes a piston and said wedge means includes a pair of cones, each of said cones being engageable with the die segments of one of said inner dies.

References Cited by the Examiner UNITED sTATEs PATENTS 442,598 12/1890 Knight 72 393 1,838,892 12/1931 Vis 72 393 1,926,400 9/1933 Palmer 72- 393 1,997,323 4/1935 Strand 72-355 2,122,04 6/1938 Powell 72 393 2,292,054 8/1942 Cleveland 72-393 2,442,965 6/1948 Thomas 72-393 2,826,161 3/1958 Palmer 72-354 CHARLES W. LANHAM, Primary Examiner.

RICHARD J. HERBST, Examiner. 

1. AN APPARATUS FOR FORMING A RIM FROM AN ANNULAR BLANK INCLUDING OUTER DIE MEANS OPERABLE TO CONFINE THE BLANK ON THE RADIALLY OUTER PERIPHERY THEREOF, A PAIR OF OPPOSITELY MOVABLE RAMS MOVABLE AXIALLY INTO THE BLANK, A PAIR OF INNER DIES CARRIED ONE ON EACH OF SAID RAMS, EACH OF SAID INNER DIES COMPRISING A PLURALITY OF DIE SEGMENTS ENGAGEABLE WITH THE RADIALLY INNER PERIPHERY OF A BLANK ENCLOSED BY SAID OUTER DIE MEANS TO FORM SAID RIM UPON THE MOVEMENT OF SAID RAMS TOWARD ONE ANOTHER, AND WEDGE MEANS CARRIED BY EACH OF SAID RAMS FOR RADIALLY EXPANDING SAID DIE SEGMENTS AND MEANS FOR ACTUATING SAID WEDGE MEANS UPON THE COMPLETION OF THE MOVEMENT OF SAID RAMS TOWARD ONE ANOTHER. 